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Organics in water column

kokzhilee

New Member
Nov 1, 2022
18
35
Missouri
Accumulated organics are one of the triggers for algae bloom. I have some questions:

1. Is there test kit for testing the quantity of organics in the water column?

2. Besides water change, is there any (filter related or other) product that can remove organics in planted tanks? Looking for something that can be regenerated if there’s one.
 
The only way you can really test for organics is by testing your TDS. If you do a water change with 120 TDS water, add 60 TDS worth of fertilizers, and your tank is registering 240 TDS at the end of the week, then you have roughly 60 TDS worth of dissolved organics. Exceptions to this would be any rock that leeches CA/MG.

There are a few different things that you should be doing to help prevent buildup of organic waste.

First and foremost (as you pointed out) is changing your water at least once a week. It’s not nearly as simple as just draining and refilling, however. You should be intentionally disturbing the top ½” or so of substrate to get any accumulated gunk out of there, getting in and around plant groupings with your syphon hose, and even pulling really dense groupings once a month or so to get in there really well. You can syphon right through densely planted carpeting plants like DHG, HC Cuba, or MC by just gently pressing the syphon on top of the carpet.

Before doing the water change, go through each plant grouping and find / trim any dead, dying, or damaged leaves. A dying leaf isn’t contributing to the health of the plant, and is leeching organics into the water column while being an algae magnet itself.

Organics also live inside your filter sponges and floss, so rinsing / replacing these will remove organics from the system. Personally I change my fine filter pad and floss every two weeks, as well as rinsing the coarse sponges. If you have a pre-filter that’s easily accessible, you can clean that as often as possible. I clean mine every week during my water change.

As far as products designed to remove organics, the only one that comes to mind is Seachem Purigen. There is debate to be had over whether or not it works, but most would agree that it only should be used as a supplement to proper tank husbandry, not as a supplement replacement.

@GreggZ is a fanatic for tank maintenance, and I’m sure he’ll be coming along with a whole host of other ideas.
 
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@GreggZ is a fanatic for tank maintenance, and I’m sure he’ll be coming along with a whole host of other ideas.
I agree with everything you said.

First and foremost are large water changes. If your TDS has risen, it might take several back to back to "reset" the water column.

And then everything mentioned above. Regular pruning/removal of dead/decaying plant matter, frequent filter cleanings, regular gravel vacs......just good general maintenance and good old fashioned elbow grease.

Also pay attention to fish feeding. Overfeeding is a large contributor to dissolved organics. Fish need are less food than people think. I feed my large tank full of Rainbows very lightly, and only once a day, or once every other day.

Overstocking is another problem. Especially with lot of "clean up" crews like pleco's/BN's that create a LOT of waste.

As to Purigen I have used it in the past, but saw no meaningful benefit, other than super crystal clear water immediately after adding it. But really had no effect on TDS.

For me I test TDS right before and right after every change. I also keep those records in a spreadsheet. If I notice it is rising or has risen, then something is off and causing it. So I roll up the sleeves and clean things thoroughly and perform large water changes. That brings it right back down where it should be.
 
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1. Is there test kit for testing the quantity of organics in the water column?
Patassium Permanganent is a good way to check organics. It will kill all life if not used properly so be aware. There are many tutorials online about dosing it to figure out how much organics your tank has. Basically the color idicates how much you have.
 
Dissolved organics will not show up on a TDS meter. They have no charge.
My friend Michael on ukaps has a ORP meter and a few others aswell to measure pollution in tanks. Mike's fish room musings
Some good reading and links to do if you look round the forum
I'm not sure this is entirely true. To what can we attribute rising TDS in a neglected tank that doesn't get a water change?
 
I'm not sure this is entirely true. To what can we attribute rising TDS in a neglected tank that doesn't get a water change?
Agreed.

I can site many places where it states that TDS meters measure both dissolved inorganic and organic substances, the 2hr Aquarist being one of them. Now does that make it true? Not necessarily.

But even if not I would argue that the by products of dissolved organics show up in the reading. Over feed, neglect a tank, let stuff rot, and I guarantee you TDS rises. Seen it many times over.
 
While I understand our theory that dissolved organics lead to algae but I think this is one of those items that simply can't be measured accurately. I also think that establishing a "correct" number would be difficult as it would likely vary quite a bit for each tank.

Like a lot of things, you will know when you have too much. Then it's time to run maintenance and reduce the amount.
 
Dissovled Organic Ccarbon, (DOC's) certainly can be measured, but it's more a BOD test, you can also do a COD test as a substitute.

In aquariums you can have VERY higher DOC ppms and zero algae.

It's not a set amount or a type specifically. It's more the draw upon the available O2 ppm in the aquarium.
If something is rotting in the plant tank, it'll suck a lot of O2 out. The RATE of the O2 removal to oxidize say, a rotting Aponogeton bulb, or dying roots, or a filter that's suddenly clogged(or a vacillation every week, few days, or monthly), or something that slows the growth down of the plants, which this vacillation can cause, these are things that lead to the algal issues for most cases, rather than some DOC ppm.

Take our friend the Tannins group, wide range of DOC's but does not cause algae. the Type of DOC's count and the Rate.
COD will help some, BOD as well but more complicated and I'm not sure BOD will be too helpful vs COD.

At the end of the day, DOC's are just a correlation, rather than a cause of algae and related strongly to poor, even if temporary/vacillating plant growth.

If you have a canister filter, clean the sucker more often. Changes in flow causes drops in the O2, less CO2, and poor plant health in many cases.

You can always do the default test for ANY ppm of DOC, nutrients etc. .....ye old Large and Frequent water changes.
That often times will not resolve the algal issues though. So lowered DOC does not make algae go away or cure the issue.
You could still argue that a rise in DOC's of some sort causes some algae blooms. But if the drop off is plant health, lower growth rates, rotting stuff, lack if filter flow, poor CO2/clogged diffusers........are NOT the causes(I would suggest those things are much more the root causes for issues), then perhaps. Liebig's law added other things like Temp, Flow(water in our case), CO2, light etc. Not just nutrients or DOC's. I mean you can hammer the DOC's, but why do you have them to begin with? At last the types that do cause algae? And the corollary to that is why doesn't the algae go after after you remove the DOC's? Probably because the root issue regarding plant growth has not been fixed. You can make assumptions about DOC's and algae all day long, does that fix algae or plant growth problems? Not really.

Does looking at how to get that old Plank bucket of Liebig's to fill up higher(Better plan growth) help? Virtually in every case.

I left for a little over 2.5 weeks, the CO2 ran out of course, water changes were done by a friend 2x a week, 70%. Oh you bet I got algae.
When I got back, the friend felt they had caused it all. I said no, my bad for not just swapping a new tank before going on Vacation. I'd say this is a pretty foul outbreak of one of the tougher types of algae to get rid of.

3 days later? Clean. Did not come back, I did a big water change, cleaned the plants, filter, added a new CO2 tank, then another water changes 2 days later just because and another one 3 more days later. 2nd pic is 3 days after fixing the issue. Now if your CO2 gas tank runs out and you do not catch that issue, it's pretty obvious reason why. But other reasons, like filter clogged, then that causes the CO2 to be not high enough etc, or the filter is clogged and going slightly anoxic(DOC source) and the reduced flow lowers the O2 ppms a bit, say 2 ppm, which is a lot. There are so many ways to nut something up. So unless things are growing well, and you want to purposely try to induce algae, it's much harder to see things clearly.
Why? You lack a "control".
 

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Based on @GreggZ experience on the Purigen, which cleans the water without affecting TDS, suggesting TDS meter doesn't fully reflect what is in the water. Whether the removed stuff is organic matter is another story.

According to google, TDS measures the conductivity in water. If more salt, which dissolves as ions (Na+ and Cl-), is in the water, the conductivity increases and TDS detects that. So if something dissolves in water but won't affect conductivity, then the TDS meter can't detect that.

Typical organics include carbohydrates, lipids, proteins, and nucleic acids. Each has different varieties and forms (charged or not charged). Only the charged molecules conduct current and affect conductivity.

Thus, not all organics can be detected by a TDS meter.
@BigWave Thanks for suggesting the Potassium permanganate. It seems like a good test for measuring organics as it changes color after oxidizing organics. The color-changing spectrum is purple>blue>green>orange>yellow (chemical chameleon reaction). More yellow = more organics. The only downside is that if the organic is fully oxidized, then the color won't change. The good news is most if not all biological organics can be oxidized. This might be the simplest test before the standard DOC or COD routes.

Thanks everyone for chiming in. I learned something new and have a better idea about organic matter.
 
I appreciate the conversation and the thinking involved with the posts. For me, I'm not sure I care about the actual level of DOC in the water. I do care if it is high or trending up. Perhaps ORP is a better tool if that's what you're after? http://reefkeeping.com/issues/2003-12/rhf/feature/index.htm
 
So far the best method I have found to reduce dissolved organics in the water is to simply remove organics before they can dissolve. Little things like cleaning up dying leaves frequently goes a long way.

During water changes I now try to siphon as much debris from the bottom of my tank as possible. Turkey baster to kick up debris into siphon does a great job at this. If you haven't tried this I would recommend. It takes a little practice but will make your tank a lot more clean long-term.

Good flow and mechanical filtration can also help out a lot I think but with delicate stems this isn't really viable for me personally.

Like others said if your water is too dirty to maintain you can do some large water changes in quick succession to reset at any time. I feel like any dirty tank can be resolved in a matter of ~2-3 big water changes with diligent removal of waste during siphon.

I feel that getting efficient at tank maintenance is really important for this reason.
 
So far the best method I have found to reduce dissolved organics in the water is to simply remove organics before they can dissolve. Little things like cleaning up dying leaves frequently goes a long way.

During water changes I now try to siphon as much debris from the bottom of my tank as possible. Turkey baster to kick up debris into siphon does a great job at this. If you haven't tried this I would recommend. It takes a little practice but will make your tank a lot more clean long-term.

Good flow and mechanical filtration can also help out a lot I think but with delicate stems this isn't really viable for me personally.

Like others said if your water is too dirty to maintain you can do some large water changes in quick succession to reset at any time. I feel like any dirty tank can be resolved in a matter of ~2-3 big water changes with diligent removal of waste during siphon.

I feel that getting efficient at tank maintenance is really important for this reason.
Agreed.

An uber clean well maintained tank makes every single other thing easier. But it's not as interesting a topic as ferts or lights so is not discussed as often. But if you get to know some of the best in the hobby, that is the one thing they have in common.
 
Agreed.

An uber clean well maintained tank makes every single other thing easier. But it's not as interesting a topic as ferts or lights so is not discussed as often. But if you get to know some of the best in the hobby, that is the one thing they have in commo

Definitely, I also believe that issues start arising before you visibly see algae or other plant deficiencies so being proactive is very important as opposed to reacting to a problem. You might not need 50-70% WC but you won't know that until an issue develops. Once the issue develops you're playing catchup and not getting the full potential from your plants.

The less maintenance you do, the more restricted you are in what you can grow, the light you can use and the livestock you can keep IMO.
 
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